The fourth installment of the insanely popular Monster Rancher series adds adventure, RPG, and storyline elements to its basic simulation mode. For the first time in the series players can do more than just breed, raise, and train monsters, they can go on adventures with them. Also newly added is the ability to breed and train multiple monsters simultaneously. Customizable training facilities allow players to create the best possible training program for their monsters. Unlock new monsters by playing your favorite CDs and DVDs with Monster Rancher 4 with the innovative disk Swapping Feature.